I have been using Pyramid PR326 strings on my Yasuma Model 130 acoustic (Dreadnought, cedar top, mahogany back & sides) for over a year. They transformed the sound of this guitar, which I have owned for 35 years! They offer me the warm, complex, balanced tone that I value and which I have not yet found in other phosphor bronze strings (including other round-core types). The polished finish does improve their playability and I find they last a long time.